JP5733092B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, and more particularly, to a semiconductor device having a first semiconductor element and a second semiconductor element and a manufacturing method thereof.

  Conventionally, a power module that performs voltage conversion or power conversion of DC voltage, and includes a high-side electrode plate and a low-side electrode plate that respectively receive a high-order side and a low-order side of a DC voltage, and a high-side electrode plate and a low-side electrode plate First and second switching elements connected in series between each other, and a middle side electrode plate connected to an intermediate point between the first switching element and the second switching element, the first switching element and the second switching element The switching element is configured by laminating a common middle-side electrode plate, and a power module is known in which the elements are stacked in a high density (see, for example, Patent Document 1). In such a power module, the upper and lower arms sandwiching the middle side electrode are integrally molded with a sealing resin.

JP 2006-49542 A

  However, in the configuration described in Patent Document 1 described above, when ultrasonic bonding is used to inspect the quality of solder bonding near the surface of the middle side electrode and the quality of bonding between the sealing resin and the middle side electrode, ultrasonic waves are used. Passes through multiple layers of solder layers, electrodes, and semiconductor elements, and reaches the inspection target region. Therefore, the reflected wave is significantly attenuated, and the soldering quality near the middle side electrode is accurately determined and the sealing resin. There is a problem that it is difficult to inspect whether or not the middle side electrode is bonded.

  FIG. 1 is a diagram showing a conventional two-stage stacked power module described in Patent Document 1. In FIG. FIG. 1A is a cross-sectional configuration diagram of a conventional two-stage stacked power module. In FIG. 1A, a lower arm 310 is laminated on an upper arm 320. In the upper arm 320, the semiconductor switching element 211 and the rectifying element 221 are joined to the high side electrode 260 by the solder 290, and the spacer electrode 230 is further laminated thereon via the solder 290, and further on the solder 290 via the solder 290. The middle side electrode 250 is laminated. Further, a control terminal 271 is connected to the semiconductor switching element 211 via a bonding wire 280.

  On the middle side electrode 250, the lower arm 310 is configured by laminating the semiconductor switching element 210 and the rectifying element 220, the spacer electrode 230, and the low side electrode 240, which are also joined by the solder 290. Further, a control terminal 270 is connected to the semiconductor switching element 210 via a bonding wire 280. The components other than the low-side electrode 240, the middle-side electrode 250, the high-side electrode 260, and the control terminals 270 and 271 that extend to the side are molded by the sealing resin 300 and integrated. Such a configuration can be made compact by stacking the upper arm 320 and the lower arm 310 and sharing the middle side electrode 250 of both.

  FIG. 1B is a diagram for explaining the problems of inspection by ultrasonic flaw detection of a conventional two-stage stacked power module. As shown in FIG. 1B, in ultrasonic flaw detection, ultrasonic waves are applied toward the power module. The incident wave of the ultrasonic wave is an ultrasonic wave of several tens MHz output from the oscillator, and the reflected wave reflected from the interface between the sealing resin 300 and the electrodes 240, 250, 260 is detected by the sensor, and the intensity is detected. To do. When the object to be inspected is composed of materials having different ultrasonic propagation speeds, the ultrasonic waves have a property of reflecting at the interface where the propagation speed changes. The reflected wave intensity increases as the difference in propagation speed of the substance across the interface increases. In general, a gas such as air has a significantly different propagation speed than solids. Therefore, if there is a release layer that is not in close contact with the interface between constituent materials, there is an air layer, so that a strong reflected wave is generated compared to a normal case without the release layer, and this can be detected clearly. The ultrasonic flaw inspection utilizes this property to inspect the adhesion between the sealing resin and the electrode.

  By the way, the sealing resin 300 is insulated from the periphery of the semiconductor, a portion where a high voltage is applied, such as a bonding wire, prevention of intrusion of water or contaminants from the outside to the periphery of the semiconductor, the bonding wire, etc., and suppression of thermal deformation. There are three functions. The suppression of thermal deformation means that the linear expansion coefficients of the semiconductor (silicon) and the electrode (copper) are different, so that stress is generated at the interface between the two due to temperature change, and the solder layer 290 that joins the semiconductor and the electrode is damaged. The phenomenon that occurs is to suppress the sealing resin having a linear expansion coefficient close to that of copper. These three functions do not appear unless the sealing resin 300 and the electrodes 240 to 260 are in close contact with each other. Therefore, it is very important to inspect the adhesion between the sealing resin 300 and the electrodes 240 to 260 by ultrasonic flaw detection. It is equally important to inspect the solder 290 for voids or the like.

  As shown in FIG. 1B, the inspection of the interface between the sealing resin 300 and the electrodes 240 to 260 is performed by making ultrasonic waves enter from the low side electrode 240 side or the high side electrode 260 side. Here, since the interface between the low-side electrode 240 and the sealing resin 300 is performed by the incident wave C and the reflected wave D that only pass through the low-side electrode 240, the propagation distance is short and there is no large shape change. / N signal can be obtained and inspected. Since the interface between the high side electrode 260 and the sealing resin 300 is also formed by the incident wave C ′ and the reflected wave D ′ having a short propagation distance, there is no problem.

  However, the incident wave A and the reflected wave B, the incident wave A ′ and the reflected wave B ′ at the interfaces with the sealing resin 300 on both surfaces of the middle side electrode 250 are divided into the three solder layers 290, the spacer electrode 230, and the semiconductor. Since it is necessary to pass through the switching element 210, the rectifying element 220, etc., a phenomenon occurs in which the ultrasonic wave is attenuated during this period. In addition, a phenomenon that the signal is disturbed also occurs because the ultrasonic wave passes through the stacked layers. As a result, there is a problem that a sufficient S / N signal cannot be obtained, and the adhesion between the middle side electrode 250 and the sealing resin 300 cannot be accurately inspected.

  Therefore, an object of the present invention is to provide a semiconductor device and a method for manufacturing the same that can accurately inspect the state of bonding with a sealing resin and solder bonding at the interface of the middle side electrode.

In order to achieve the above object, a semiconductor device according to one embodiment of the present invention includes a first semiconductor element, and is formed on each surface of the first semiconductor element so as to sandwich the first semiconductor element from both sides. A first resin mold that is conductively provided with a low-side electrode and a first middle-side electrode, and is molded with a sealing resin so that an outer surface of the low-side electrode and the first middle-side electrode is exposed;
A second semiconductor element, and a high-side electrode and a second middle-side electrode are provided in conduction with each surface of the second semiconductor element so as to sandwich the second semiconductor element from both sides, A second resin mold molded with a sealing resin so that the outer surfaces of the high side electrode and the second middle side electrode are exposed;
The outer surfaces of the first middle side electrode and the second middle side electrode are bonded together by a bonding material having no conductivity,
The first middle side electrode and the second middle side electrode each have a first extraction electrode portion and a second extraction electrode portion that protrude outward from the side surface of the sealing resin,
The first lead electrode portion and the second lead electrode portion are electrically connected by bonding.

In the method for manufacturing a semiconductor device according to another aspect of the present invention, the first semiconductor element is disposed between the low-side electrode and the first middle-side electrode, and the first semiconductor element 2 is formed by solder bonding. In a state where the surface, the low side electrode and the first middle side electrode are conductively fixed, molding is performed with a sealing resin so that the outer surface of the low side electrode and the first middle side electrode is exposed. A first resin mold forming step of forming one resin mold;
The second semiconductor element is disposed between the high-side electrode and the second middle side electrode, conducting said two faces the high-side electrode and the second middle side electrode of the semiconductor element of the second by solder joint A second resin mold forming step of forming a second resin mold by molding with a sealing resin so that the outer surfaces of the high side electrode and the second middle side electrode are exposed in a fixed state When,
A first resin mold inspection step of inspecting an interface between the low side electrode and the sealing resin of the first resin mold and an interface between the first middle side electrode and the sealing resin by ultrasonic flaw detection;
A second resin mold inspection step of inspecting an interface between the high side electrode and the sealing resin of the second resin mold and an interface between the second middle side electrode and the sealing resin by ultrasonic flaw detection;
In the first resin mold inspection step and the second resin mold inspection step, the first middle side electrode of the first resin mold and the second resin mold that are determined as non-defective products, and the second resin mold have the outer surface between the middle side electrodes, Rutotomoni to adjust contact by no bonding material conductivity, the integrated process for conducting the wherein the first middle side electrode and the second middle side electrodes, the And
The first middle side electrode and the second middle side electrode each have a first extraction electrode portion and a second extraction electrode portion that protrude outward from the side surface of the sealing resin,
Conductivity between the first middle side electrode and the second middle side electrode in the integration step is performed by joining the first lead electrode portion and the second lead electrode portion. To do.

  According to the present invention, the state of the interface of the middle side electrode can be accurately inspected, and the reliability of the semiconductor device can be improved.

It is the figure which showed the conventional 2 step | paragraph laminated type power module. FIG. 1A is a cross-sectional configuration diagram of a conventional two-stage stacked power module. FIG. 1B is a diagram for explaining the problems of inspection by ultrasonic flaw detection of a conventional two-stage stacked power module. It is sectional drawing which showed an example of the semiconductor device which concerns on Example 1 of this invention. FIG. 6 is a diagram for explaining inspection by ultrasonic flaw detection of the semiconductor device according to the first embodiment. FIG. 3A is a view for explaining inspection by ultrasonic flaw detection of the lower arm. FIG. 3B is a diagram for explaining inspection by ultrasonic flaw detection of the upper arm. 6 is an explanatory diagram of a method for joining the upper arm and the lower arm of the semiconductor device according to the first embodiment. FIG. It is a figure for demonstrating the procedure of the soldering of the semiconductor device which concerns on Example 1, and a molding. FIG. 5A is a diagram illustrating an example of an element soldering process of the lower arm 110. FIG. 5B is a diagram illustrating an example of a low-side electrode soldering process. FIG. 5C is a diagram illustrating an example of a resin mold forming process. It is the figure which showed the soldering process of the conventional semiconductor device as a comparative example. FIG. 6A is a diagram showing an element soldering process. FIG. 6B is a diagram showing an electrode soldering process. It is the figure which showed an example of the structure of the upper arm and lower arm of a semiconductor device which concern on Example 2 of this invention, and a joining process. It is the figure which showed an example of the semiconductor device which concerns on Example 3 of this invention. It is the figure which showed an example of the semiconductor device which concerns on Example 4 of this invention. It is the figure which showed an example of the semiconductor device which concerns on Example 5 of this invention. FIG. 10 is a diagram illustrating an example of a configuration of a joint in a second motor drive circuit according to a fifth embodiment. FIG. 10 is a diagram showing another example of the configuration of the joint in the second motor drive circuit of the fifth embodiment. It is the figure which showed the structure of the 1-stage power module single-piece | unit of Example 5. FIG. 13A is a perspective view showing an external appearance of a single-stage power module. FIG. 13B is a circuit diagram of a single stage power module. FIG. 13C is a cross-sectional view of a double-sided cooling power module. FIG. 10 is a diagram illustrating an example of an inverter circuit of a second motor drive circuit according to a fifth embodiment. FIG. 10 is a diagram illustrating a cross-sectional configuration of an inverter circuit of a second motor drive circuit according to a fifth embodiment. FIG. 15A is a cross-sectional configuration diagram of an inverter circuit. FIG. 15B is a perspective view of the inverter circuit. FIG. 10 is an exploded perspective view of a semiconductor device according to a fifth embodiment. It is sectional drawing which showed an example before joining of the semiconductor device which concerns on Example 6 of this invention. FIG. 10 is a diagram illustrating an example after bonding of a semiconductor device according to Example 6; It is sectional drawing which showed an example of the semiconductor device which concerns on Example 7 of this invention. It is sectional drawing which showed an example of the semiconductor device which concerns on Example 8 of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 2 is a cross-sectional view showing an example of a semiconductor device according to Example 1 of the present invention. In FIG. 2, the semiconductor device according to the first embodiment includes a lower arm 110 and an upper arm 120. The lower arm 110 is a resin mold body on which a low side circuit is mounted, and the upper arm 120 is a resin mold body on which a high side circuit is mounted. The low side circuit means a circuit on the low potential side when the circuit is composed of two stages of a low potential side and a high potential side, and the high side circuit means a circuit on the high potential side. The semiconductor device according to the first embodiment will be described with an example configured as a two-stage stacked power module.

  The lower arm 110 includes a first semiconductor element 10, a first rectifying element 20, a spacer electrode 30, a low side electrode 40, a first middle side electrode 50, a first control terminal 70, and a bonding The wire 80, the solder 90, and the sealing resin 100 are provided.

  The upper arm 120 includes the second semiconductor element 11, the second rectifying element 21, the spacer electrode 30, the second middle electrode 51, the high side electrode 60, and the second control terminal 71. Bonding wire 80, solder 90, and sealing resin 100 are provided.

  Here, the spacer electrode 30, the bonding wire 80, the solder 90, and the sealing resin 100 are common to the upper arm 110 and the lower arm 120 since there is no difference between them, and thus the same reference numerals are given.

  In the semiconductor device according to the present embodiment, the upper arm 110 and the lower arm 120 are individually provided with the middle side electrodes 50 and 51, and each is individually sealed with resin. As described with reference to FIG. 1, the conventional two-stage stacked power module has a common middle side electrode 250 and is sealed with the low side electrode 240 and the high side electrode 250 together. However, the semiconductor device according to the present embodiment is different in that the lower arm 110 and the upper arm 120 are individually resin-sealed and configured as separate bodies.

  In the lower arm 110, the first semiconductor element 10 and the first rectifying element 20 are joined to the first middle side electrode 50 by solder 90. Further, a spacer electrode 30 is bonded and laminated on the first semiconductor element 10 and the first rectifying element 20 by solder 90. On the spacer electrode 30, the low-side electrode 40 is laminated so as to cover both the first semiconductor element 10 and the first rectifying element 20 through the solder 90. And it mold-molds with the sealing resin 100 so that the outer surface of the low side electrode 40 and the 1st middle side electrode 50 may be exposed, and the 1st resin mold body is formed. The first middle side electrode 50 has a first extraction electrode portion 50 a that extends horizontally to the right side and protrudes outward from the sealing resin 100 and is exposed. Further, on the left side of the first middle side electrode 50, the first control terminal 70 is arranged at a level substantially horizontal to the middle side electrode 50 so that the tip protrudes from the sealing resin 100 and is exposed. The remaining part is sealed with a sealing resin 100. The first control terminal 70 and the first semiconductor element 10 are connected by a bonding wire 80.

  The upper arm 120 has substantially the same configuration as the lower arm 110, but the high-side electrode 60 is disposed at the lower end, and the second semiconductor element 11 and the second rectifying element are joined by bonding using the solder 90 thereon. 21, the spacer electrode 30, and the second middle side electrode 51 are stacked in order from the bottom. The second middle side electrode 51 is different from the first middle side electrode 50 in that it does not have a lead electrode portion. The second control terminal 71 is disposed on the left side of the high-side electrode 60, the tip protrudes from the sealing resin 100 and is exposed, and a portion in the sealing resin 100 is bonded to the second semiconductor by the bonding wire 80. The point connected to the element 11 is the same as that of the lower arm 110.

  As described above, the lower arm 110 and the upper arm 120 are once separately and independently formed. Finally, the first middle side electrode 50 and the second middle side electrode 51 are joined or pressed together, and are fixed integrally. The state in which the lower arm 110 and the upper arm 120 are fixed by joining or press-contacting is a state completed as a power module.

  In FIG. 2, switching elements using semiconductors are used for the first and second semiconductor elements 10 and 11. For example, semiconductor switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and power MOS (Metal Oxide Semiconductor) transistors may be used for the first and second semiconductor elements 10 and 11. Further, the same semiconductor element may be used for the first semiconductor element 10 and the second semiconductor element 11.

  For the first and second rectifying elements 20 and 21, diodes having a rectifying action may be used. For example, the first and second rectifying elements 20 and 21 may be connected in parallel with the collector-emitter (or between the drain and source) of the first and second semiconductor elements 10 and 11. When the first and second semiconductor elements 10 and 11 are IGBTs and the semiconductor device according to this embodiment is configured as an inverter, the first and second rectifying elements 20 and 21 The two semiconductor elements 10 and 11 are connected in parallel between the collector and the emitter.

  The spacer electrode 30 secures a gap between the low side electrode 50 and the first middle side electrode 50 and a gap between the high side electrode 60 and the second middle side electrode 51, and the first and second semiconductor elements 10, 11 is an electrode for facilitating the release of heat generation. In addition, since the spacer electrode 30 is one of the electrodes, conduction between the first semiconductor element 10 and the low-side electrode 40 and conduction between the second semiconductor element 11 and the second middle-side electrode 51 are ensured. The spacer electrode 30 may be configured as an electrode such as a columnar block having a smaller area than the first and second semiconductor elements 10 and 11 and the first and second rectifying elements 20 and 21. Therefore, the space electrode 30 may be called a block electrode. The space electrode 30 may be made of various metals, but is preferably made of a wiring metal such as copper or aluminum.

  The low side electrode 40 is an electrode having the same potential as the potential line on the low potential side of the low side circuit of the lower arm 110. The low side electrode 40 is set to a ground potential, for example. The low-side electrode 40 has a larger area than the first semiconductor element 10 and the first rectifier element 20 so as to cover both the first semiconductor element 10 and the first rectifier element 20, and has a flat plate shape. It is formed as an electrode. The low side electrode 40 may also be made of various metals, but is preferably made of a wiring metal such as copper or aluminum.

  The first middle side electrode 50 is an electrode serving as an output terminal of the low side circuit, and has the same potential as the potential line on the high potential side of the low side circuit. Similarly to the low-side electrode 40, the first middle-side electrode 50 is also formed as a plate-like electrode having an area that covers both the first semiconductor element 10 and the first rectifying element 20. The first middle side electrode 50 may also be made of various metals, but is preferably made of a wiring metal such as copper or aluminum.

  The second middle side electrode 51 is an electrode serving as an output terminal of the high side circuit, and has the same potential as the potential line on the low potential side of the high side circuit. The second middle side electrode 51 also has an area covering both the second semiconductor element 11 and the second rectifying element 21 and is formed as a flat electrode. The second middle side electrode 51 may also be made of various metals, but is preferably made of a wiring metal such as copper or aluminum.

  The first middle side electrode 50 and the second middle side electrode 51 are integrally fixed by physical bonding or pressure welding, and are also electrically connected. Therefore, the first middle side electrode 50 and the second middle side electrode 51 constitute an output terminal having the same potential. In FIG. 2, the extraction electrode portion 50 a is provided only on the first middle side electrode 50, and this extraction electrode portion 50 a serves as a common output terminal for the lower arm 110 and the upper arm 120. Moreover, since the 1st middle side electrode 50 and the 2nd middle side electrode 51 are joined or press-contacted, it is preferable that an outer joining surface is formed jointly.

  The high side electrode 60 is an electrode having the same potential as the potential line on the high potential side of the high side circuit. For example, the high side electrode 60 is set to the same potential as the power supply. Note that the high-side electrode 60 is also formed as a flat electrode having an area that can cover both the second semiconductor element 11 and the second rectifying element 21. The high side electrode 60 may also be made of various metals, but is preferably made of a wiring metal such as copper or aluminum.

  The first control terminal 70 is a terminal for supplying a control signal to the first semiconductor element 10. When the first semiconductor element 10 is an IGBT or a power MOS transistor, the first control terminal 70 is connected to the gate of the first semiconductor element 10 to control on / off of the first semiconductor element 10. To do.

  The second control terminal 71 is a terminal for supplying a control signal to the twenty-first semiconductor element 11, and the configuration and function thereof may be the same as those of the first control terminal.

  The bonding wire 80 is a wiring wire for connecting the first and second control terminals 70 and 71 and the first and second semiconductor elements 10 and 11, respectively. Specifically, for example, the gates of the first and second semiconductor elements 10 and 11 and the first and second control terminals 70 and 71 are connected by wire bonding, respectively.

  The solder 90 is a bonding material for bonding the components in the stacking direction. Since the solder 90 is a conductive bonding material, the components are not only physically bonded but also electrically connected. Specifically, in the lower arm 110, the solder 90 is composed of the first middle-side electrode 50, the first semiconductor element 10, the first rectifier element 20, the first semiconductor element 10, the first rectifier element 20, and the spacer. The electrode 30, the spacer electrode 30, and the low side electrode 40 are joined, and they are also electrically connected. Similarly, in the upper arm 120, the solder 90 is composed of the high-side electrode 60, the second semiconductor element 11, the second rectifying element 21, the second semiconductor element 10, the second rectifying element 20, the spacer electrode 30, and the spacer electrode. 30 and the second middle side electrode 51 are physically joined and electrically connected.

  The sealing resin 100 is a material for sealing the components of the lower arm 110 and the upper arm 120, ensuring insulation between the components, and protecting the components from external moisture, moisture, dust, and the like. The sealing resin 100 is formed into a shape as shown in FIG. 2 by molding. In addition, it is preferable that the material of the sealing resin 100 is selected and adjusted so as to be close to the linear expansion coefficient of each of the electrodes 30 to 60. For example, when copper is used for the electrodes 30 to 60, an epoxy resin is used for the sealing resin 100, and other inorganic substances or organic substances are mixed so as to be close to the linear expansion coefficient of copper. Also good.

  FIG. 3 is a diagram for explaining the inspection by the ultrasonic flaw detection of the semiconductor device according to the first embodiment. FIG. 3A is a view for explaining inspection of the lower arm 110 by ultrasonic flaw detection. In FIG. 3A, the lower arm 110 is configured by disposing the low side electrode 40 on the upper side and the first middle side electrode 50 on the lower side. When an ultrasonic wave is emitted toward the surface of the low side electrode 40 in this state, the incident wave C passes only through the low side electrode 40 and is reflected at the interface between the low side electrode 40 and the sealing resin 100 to obtain a reflected wave D. It is done. Therefore, a sufficient S / N signal can be obtained as the reflected wave D. This is the same as the conventional power module described in FIG.

  On the other hand, even when an ultrasonic wave is emitted toward the surface of the first middle side electrode 50, the incident wave A passes only through the first middle side electrode 50, and the first middle side electrode 50 and the sealing resin 100. And reflected wave B can be obtained. That is, the direct reflected wave from the interface of the first middle side electrode 50 also does not pass through the solder 90, the first semiconductor element 10, the spacer electrode 30, and the like at the interface of the first middle side electrode 50. B can be obtained. Therefore, the reflected wave B is a signal having a sufficient S / N, and the adhesion with the sealing resin 100 at the interface of the first middle side electrode 50 can be accurately inspected.

  Thus, in the lower arm 110, since the surfaces of the low-side electrode 40 and the first middle-side electrode 50 are both exposed, the adhesion with the sealing resin 100 at the interface between both the electrodes 40 and 50 is improved. It can be accurately inspected.

  FIG. 3B is a view for explaining inspection of the upper arm 120 by ultrasonic flaw detection. In FIG. 3B, the upper arm 120 is disposed such that the second middle side electrode 51 is on the upper side and the high side electrode 60 is on the lower side. Also in this case, since the surface of the second middle side electrode 51 is exposed, by emitting ultrasonic waves toward the second middle side electrode 51, the incident wave A ′ and the reflected wave B ′ are Reflects only through the second middle side electrode 51. Therefore, the reflected wave B ′ is a signal having a sufficient S / N, and the adhesion between the interface of the second middle side electrode 51 and the sealing resin 100 is accurately inspected by detecting this with a sensor. And increase its reliability.

  At the interface of the high side electrode 60, the incident wave C ′ and the reflected wave D ′ pass through only the high side electrode 60, so that a signal can be detected with high S / N, and the high side electrode 60 can be accurately detected. The adhesion with the sealing resin 100 at the interface can be inspected.

  Thus, according to the semiconductor device according to the present embodiment, since both the lower arm 110 and the upper arm 120 perform resin sealing with the middle side electrodes 50 and 51 exposed, the middle side electrode 50 and 51 and the sealing resin 100 can be accurately inspected, and a highly reliable semiconductor device can be provided.

  FIG. 4 is a diagram for explaining an example of a method of joining the upper arm 120 and the lower arm 110 of the semiconductor device according to the first embodiment. In FIG. 4, the same reference numerals as those in FIG.

  In FIG. 4, the first middle side electrode 50 of the lower arm 110 disposed on the upper side and the second middle side electrode 51 of the upper arm 120 disposed on the lower side face each other and are bonded via the bonding layer 130. Has been. Thus, the upper arm 120 and the lower arm 110 may be bonded via the bonding layer 130 using a bonding material.

  As the bonding material, various bonding materials can be used depending on the application. For example, a low melting point solder, a conductive adhesive, an Ag nano paste material, an In diffusion layer, or the like can be used according to the application. Since these bonding materials are all conductive materials, the first middle side electrode 50 and the second middle side electrode 51 are electrically connected by the bonding layer 130. Therefore, in the case of using a conductive bonding material, physical bonding for integrally fixing the upper arm 120 and the lower arm 110, and electrical connection between the first middle side electrode 50 and the second middle side electrode 51 are used. Both connections can be made only with the bonding layer 130.

  In addition, since joining of the upper arm 120 and the lower arm 110 is a process after resin sealing, a bonding material that can be bonded at a temperature lower than the heat resistance temperature of the sealing resin 100 is used as the bonding material. For example, a low melting point solder, a conductive adhesive, an Ag nano paste material, an In diffusion layer, or the like that can be bonded at a temperature lower than the heat resistance temperature of the sealing resin 100 is used, and the bonding material is the first middle side electrode 50 and the second middle side. It can join by inserting between the electrodes 51, heating the whole and melting or hardening a joining material. After joining, the joining material becomes the joining layer 130 as shown in FIG.

  Next, a method for manufacturing the semiconductor device according to the first embodiment will be described with reference to FIG. FIG. 5 is a diagram for explaining the procedure of soldering and molding the semiconductor device according to the first embodiment.

  FIG. 5A is a diagram illustrating an example of an element soldering process (or element joining process) of the lower arm 110. In the element soldering step, first, the first semiconductor element 10 and the first rectifying element 20 are further soldered onto the surface of the first middle side electrode 50, and the spacer electrode 30 is soldered thereon. At that time, if the solder foil is inserted into the position of the solder 90, positioned and fixed with a jig or the like and heated to melt the solder foil, as shown in FIG. The elements 10 and 20 and the electrode 30 are laminated and bonded on top. At that time, the upper surface of the spacer electrode 30 is covered with a solder material. Thereafter, the first semiconductor element 10 and the control terminal 70 are connected with an aluminum wire by wire bonding. In this state, the low side electrode 40 is prepared.

  FIG. 5B is a diagram illustrating an example of a low-side electrode soldering process (or a low-side electrode joining process). In the low-side electrode soldering step, the low-side electrode 40 is overlaid on the upper surface of the spacer electrode 30, positioned and fixed with a jig or the like, and heated to the melting point or higher of the solder material on the upper surface of the spacer electrode 30. Then, as shown in FIG. 5B, the low-side electrode 40 is soldered and joined to the upper surface of the spacer electrode 30. Thus, the wiring of the lower arm 110 is completed.

  FIG. 5C is a diagram illustrating an example of a resin mold forming process. In the resin molding process, molding is performed using the sealing resin 100. For molding, for example, a soldered product is placed in a mold of a transfer molding machine, transfer molding is performed, and the sealing resin 100 is formed around the electrodes. At that time, in order to promote the heat dissipation of the heat generated when the first semiconductor element 10 is energized, the non-semiconductor element mounting surface side (outer surface side) of the low side electrode 40 and the first middle side electrode 50 is exposed. Or when the sealing resin 100 covers a part of the electrodes 40 and 50, the non-semiconductor element mounting surface (outer surface) of the low-side electrode 40 and the first middle-side electrode 50 by cutting or the like. ) To be exposed.

  For example, the lower arm 110 is formed in this way. As for the upper arm 120, the upper arm 120 can be formed in the same manner as the lower arm 110 by replacing the first middle side electrode 50 with the high side electrode 60 and the low side electrode 40 with the second middle side electrode 51. it can.

  Thereafter, for example, as described with reference to FIG. 4, the upper arm 120 and the lower arm 110 are bonded using a bonding material, whereby the semiconductor device illustrated in FIG. 4 can be completed.

  FIG. 6 is a view showing a soldering process of a conventional semiconductor device as a comparative example. FIG. 6A is a diagram showing an element soldering process. In the element soldering process, the semiconductor element 211, the rectifying element 221, and the spacer electrode 230 are sequentially stacked on the high-side electrode 260 and joined by solder 290. The control terminal 271 is also connected to the semiconductor element 210 via the bonding wire 280. Similarly, the semiconductor element 210, the rectifying element 220, and the spacer electrode 230 are sequentially stacked on the middle side electrode 250 and joined by solder 290. A control terminal 270 is connected to the semiconductor element 210 via a bonding wire 280. Then, from the bottom, the high side electrode 260, the middle side electrode 250, and the low side electrode 240 are stacked in this order, and are positioned and fixed.

  FIG. 6B is a diagram showing an electrode soldering process. When the high-side electrode 260, the middle-side electrode 250, and the low-side electrode 240 are positioned and fixed in a superposed state and heated at a temperature at which the solder 290 on the upper surface of the spacer electrode 30 is melted, FIG. As shown, the lower arm 310 and the upper arm 320 are joined and integrated to complete wiring. In this state, the whole can be resin-sealed by performing transfer molding. At this time, the non-semiconductor element mounting surfaces (outer surfaces) of the low-side electrode 240 and the high-side electrode 260 are exposed. However, the middle side electrode 250 is structurally sealed in the sealing resin 300 (see FIG. 1).

  As described above, in the conventional semiconductor device, since molding is performed after the wiring of the semiconductor device is completed in a process, the middle side electrode 250 arranged in the middle stage is sealed after resin sealing. An inspection must be performed after being buried in the middle of the stop resin 300.

  In contrast, in the semiconductor device according to the present embodiment, since the resin sealing is completed before the bonding of the entire semiconductor device is completed, the inspection by ultrasonic flaw detection is performed with the middle side electrodes 50 and 51 exposed. It can be performed, and the adhesion with the sealing resin 100 at the interface can be inspected with high accuracy.

  FIG. 7 is a diagram illustrating an example of the configuration and joining process of the upper and lower arms of the semiconductor device according to the second embodiment of the present invention. In the second embodiment as well, the same components as those in FIGS. 2 and 4 of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 7, as in FIG. 4, the lower arm 110 is disposed on the upper arm 121, and the bonding layer 130 is formed between the second middle side electrode 52 and the first middle side electrode 50. .

  However, in the second embodiment, the second middle side electrode 52 has a lead electrode portion 52a extending rightward and protruding to the outside of the sealing resin 100, so that the semiconductor device according to FIG. Is different. In addition, a power source 140 is provided outside the semiconductor device for joining the first middle side electrode 50 and the second middle side electrode 52 and is connected to the first and second middle side electrodes 50 and 52. In this respect, the semiconductor device according to the first embodiment and the manufacturing method thereof are different.

  In the semiconductor device according to the second embodiment, the bonding between the upper arm 121 and the lower arm 110 is common in that a bonding material is used. However, the bonding material is not heated by whole heating as in the first embodiment but by energization heating. It differs in that it is joined by melting or curing.

  In FIG. 7, a power source 140 is provided and connected to the first middle side electrode 50 and the second middle side electrode 52 to apply a voltage. As described above, when a voltage is applied between the first and second middle side electrodes 50 and 52 and energized, Joule heat is generated between the first and second middle side electrodes 50 and 52, and the bonding material. Can be melted or cured. As described above, the bonding material may be melted or cured by energization.

  In the bonding method of the upper arm 120 and the semiconductor device according to the second embodiment, the bonding process is completed by a short time of energization heating until the temperature of the sealing resin 100 rises. Bonding materials can also be used. As shown in FIG. 7, the energization of the first and second middle side electrodes 50 and 52 is performed by extending a part of the middle side electrodes 50 and 52 to the outside of the sealing resin 100 and connecting the extraction electrode portion 52a. Forming or forming a hole in a part of the sealing resin 100 and inserting a power supply electrode so as to be in contact with the middle side electrodes 50, 52. May be energized.

  As described above, according to the semiconductor device and the manufacturing method thereof according to the second embodiment, the upper arm 121 is configured to have a shape capable of energizing the middle side electrode 52 from the outside, and between the middle side electrodes 50 and 52. By bonding the bonding material by melting or curing it by energization, the allowable width of the bonding material can be expanded, and a bonding material having a melting temperature or a curing temperature higher than the heat resistance temperature of the solder material can be used.

  FIG. 8 is a diagram showing an example of a semiconductor device according to Example 3 of the present invention. The semiconductor device according to the third embodiment is different from the first and second embodiments in the configuration of the second middle side electrode 53 of the lower arm 122, but the other components are the same as those in the first and second embodiments. Therefore, the other constituent elements are denoted by the same reference numerals as those in the first and second embodiments, and the description thereof is omitted.

  In the semiconductor device according to the third embodiment, the second middle side electrode 53 has a lead electrode portion 53a that protrudes and extends to the outside of the sealing resin 100, and the leading end portion of the lead electrode portion 53a is the first middle portion. The first middle side electrode 50 and the second middle side electrode 53 are electrically connected to each other at the front end portion of the side electrode 50 at the joint portion 135. In addition, the connection of the front-end | tip part of the 1st and 2nd middle side electrodes 50 and 53 may be performed by welding, riveting, caulking, etc., for example.

  In this case, since the electrical connection between the first middle side electrode 50 and the second middle side electrode 53 is ensured by the connection at the tip, the first middle side electrode 50 and the second middle side electrode 53 are connected. In the physical bonding, it is not always necessary to use a conductive bonding material. Therefore, it is possible to use a general resin adhesive having no conductivity. Further, even when a bonding material having conductivity is used, the minimum bonding layer 131 for bonding can be formed without much consideration for electrical connection.

  Therefore, as a bonding material for forming the bonding layer 131, a low-melting-point solder, a conductive adhesive, an Ag nanopaste material, an In diffusion layer, or an adhesive or pressure-sensitive adhesive having no conductivity can be used.

  According to the semiconductor device according to the third embodiment, a wide bonding material including a non-conductive adhesive or a pressure-sensitive adhesive is used for the bonding step by performing electrical connection at the tip portions of the middle side electrodes 50 and 53. Can do.

  FIG. 9 is a diagram showing an example of a semiconductor device according to Example 4 of the present invention. Also in the fourth embodiment, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted.

  In FIG. 9, the semiconductor device according to the fourth embodiment is substantially the same as the semiconductor device according to the first embodiment, but does not have the bonding layer 130 and only the pressure contact interface 132 is shown. This is different from the semiconductor device according to the first embodiment.

  In the semiconductor device according to the fourth embodiment, the second middle side electrode 51 of the upper arm 120 disposed on the lower side and the first middle side electrode 50 of the lower arm 110 disposed on the upper side face each other. It is in pressure contact. In this case, there is no bonding material at the pressure contact interface 132, and the first middle side electrode 50 and the second middle side electrode 51 are in contact and pressed. Even in such a pressure contact state, if the upper arm 120 and the lower arm 110 are fixed and the first middle side electrode 50 and the second middle side electrode 51 are sufficiently in contact with each other, they function as a power module. can do.

  For example, the pressure contact between the upper arm 120 and the lower arm 110 is performed by pressing one outer surface of the low-side electrode 40 or the high-side electrode 60 against a fixed support such as a wall, and the low-side electrode 40 or the high-side electrode 60 from the opposite side. May be performed so as to be pressed by an elastic force or the like. By using a jig, a frame, a hiding, a casing, or the like that enables such press contact, a power module can be configured without necessarily joining the first and second middle side electrodes 50 and 51 together. .

  In FIG. 9, such a jig or frame is not shown. However, for example, if a pressing force is applied from both sides of the low-side electrode 40 and the high-side electrode 60 so as to be sandwiched toward the center, Fixing can be realized.

  According to the semiconductor device according to the fourth embodiment, the semiconductor device can be configured without using a bonding material, and is used by being inserted into a jig, a frame, a casing, a housing, or the like according to an application in which the semiconductor device is used. Thus, a highly reliable power module can be configured with a simple structure.

  FIG. 10 is a diagram showing an example of a semiconductor device according to Example 5 of the present invention. In the fifth embodiment, an example in which the semiconductor device according to the fourth embodiment is configured as a drive circuit for a three-phase AC motor will be described. The semiconductor device according to the fourth embodiment is configured as an in-vehicle semiconductor device for driving a main shaft driving motor and a power generation motor of a hybrid vehicle.

  The semiconductor device according to the fifth embodiment includes a first motor driving circuit 150, a second motor driving circuit 160, a cooler fixing housing 170, a holding spring holding boss 171; a holding spring 175; and a cooling tube 180. Have

  The first motor drive circuit 150 is an inverter that drives the main shaft drive motor of the hybrid vehicle, and includes a U-phase circuit unit 151, a V-phase circuit unit 152, and a W-phase circuit unit 153.

  The second motor drive circuit 160 is an inverter that drives a power generation motor (generator) of the hybrid vehicle. The semiconductor device according to the fourth embodiment is provided corresponding to the U phase, the V phase, and the W phase.

  The cooling fixing housing 170 is a housing for fixing the cooling tube 180.

  The holding spring holding boss 171 is a boss for fixing the holding spring 175, and is fixed to the cooler fixing housing.

  The holding spring 175 presses the first motor driving circuit 150 and the second motor driving circuit 160 toward the cooler fixing haze 170 side by an elastic force via the cooling tube 180, and the first motor driving circuit 150 and the second motor are pressed. It is a pressing means for fixing the drive circuit 160.

  The cooling tube 180 is a means for cooling the drive circuits of the first motor drive circuit 150 and the second motor drive circuit 160. Cooling water circulates inside the cooling tube 180 to exchange heat generated from each circuit and cool the drive circuit. The cooling tube 180 has fins 181 inside thereof to increase the efficiency of heat exchange.

  In the semiconductor device according to the fifth embodiment, a cooling tube 180 is provided so as to sandwich the U-phase circuit unit 151, the V-phase circuit unit 152, and the W-phase circuit unit 153 of the first motor drive circuit 150 from both sides. A cooling tube 180 is also provided so as to be sandwiched from both sides of the two-motor drive circuit 160.

  In FIG. 10, the U-phase circuit unit 151, the V-phase circuit unit 152, and the W-phase circuit unit 153 of the first motor drive circuit 150 are different from the semiconductor devices according to the first to fourth embodiments. It is configured as. This is because the main shaft driving motor is a large current capacity motor, and each of the circuits 151 to 153 of the first motor driving circuit 150 has a large energization amount and a large amount of heat generation. This is because it is necessary to use a high both-side cooling method.

  On the other hand, the second motor drive circuit 160 is configured as a two-stage stacked power module as described in the first to fourth embodiments. In general, a power generation motor has a small current capacity, a small amount of power is supplied to each driving power module, and accordingly, a heat generation amount of a driving circuit is small. Therefore, a double-sided cooling method having an expensive and highly efficient cooling performance is not always necessary. In such a case, if a two-stage stacked type is used only for the driving power module having a small current capacity and a double-sided cooling system is used for this, a balance between the heat generation amount, the cooling effect and the cost can be achieved. In addition, the two-stage power module can achieve a very well-balanced configuration because it can achieve effects such as energy efficiency improvement by downsizing and low inductance.

  FIG. 11 is a diagram illustrating an example of a configuration of a joint portion in the second motor drive circuit 160. In FIG. 11, the same reference numerals as those in the fourth embodiment are given to the respective components.

  In FIG. 11, a fitting structure 101 including a convex portion 101 a and a concave portion 101 b is formed in the sealing resin 100 on the surface where the first middle side electrode 50 and the second middle side electrode 51 face each other. In FIG. 11, a concave portion 101b is formed on the lower arm 110 side, and a convex portion 101a is formed on the upper arm 120 side. Thereby, positioning of the lower arm 110 and the upper arm 120 can be performed appropriately.

  Further, in FIG. 11, the surface of the sealing resin 100 is cut lower by several μm to several tens of μm than the middle side electrodes 50 and 51. Thereby, the close_contact | adherence of the middle side electrodes 50 and 51 can be improved, and sufficient contact can be maintained only by press contact.

  FIG. 12 is a diagram illustrating another example of the configuration of the joint in the second motor drive circuit 160 of the fifth embodiment. In FIG. 12, the same reference numerals as those in the fourth embodiment are given to the respective components.

  In FIG. 12, the fitting structure 54 which consists of the convex part 54a and the recessed part 54b is formed in the opposing surface of middle side electrode 50,51. Thereby, the middle side electrodes 50 and 51 can be appropriately positioned. Further, the surface of the sealing resin 100 of the second middle side electrode 51 is lower than that of the middle side electrodes 50 and 51, as in FIG. Thereby, sufficient contact between the middle side electrodes 50 and 51 can be obtained. Note that, as shown in FIG. 12, even when only one of the middle side electrodes 50 and 51 is scraped off, the adhesion between the middle side electrodes 50 and 51 can be improved. Such a configuration may be adopted.

  As described above, the fitting structure 54 is formed on the joint surface between the upper arm 120 and the lower arm 110, and the height of the sealing resin 100 is made lower than that of the middle side electrodes 50 and 51. Can be obtained.

  In FIG. 12, two sets of the fitting structures 54 of the convex portions 54a and the concave portions 54b are shown. However, since the positioning can be performed with one or more sets, the fitting structure 54 includes at least one set of the convex portions 54a. And the recess 54b may be provided.

  Moreover, the fitting structure 54 of the convex part 54a and the recessed part 54b is not necessarily an essential structure, For example, you may make it position a power module by hold | maintaining with a jig | tool etc. from the outside. The fitting structure 54 composed of the convex portion 54a and the concave portion 54b is not necessary.

  FIG. 13 is a diagram illustrating a configuration of a single-stage power module according to the fifth embodiment. FIG. 13A is a perspective view showing an external appearance of a single-stage power module. In FIG. 13A, the power module main body 155 is sandwiched from both surfaces by the heat sink and electrode C, and the bus bar B and the control terminal 79 protrude outward.

  FIG. 13B is a circuit diagram of a single stage power module. In FIG. 13B, a semiconductor element 19 and a rectifying element 29 are connected in parallel, and an input electrode Bin and an output electrode Bout are shown.

  FIG. 13C is a cross-sectional view of a double-sided cooling power module. In FIG. 13C, the power module has a configuration in which the semiconductor element 10 and the block electrode 39 are stacked, sandwiched between the collector electrode C and the emitter electrode E, and sealed with a sealing resin 100. Further, an input bus bar Bin, an output bus bar Bout, a signal line 89 and a control terminal 79 are provided.

  FIG. 14 is a diagram illustrating an example of an inverter circuit that drives a three-phase AC motor such as the second motor driving circuit 160 according to the fifth embodiment. In FIG. 14, the low-side circuit mounted on the lower arm 111 includes semiconductor elements 12u, 12v, 12w and rectifier elements 22u, 22v, 22w corresponding to the U phase, the V phase, and the W phase. Similarly, the high side circuit mounted on the upper arm 123 includes semiconductor elements 13u, 13v, 13w and rectifier elements 23u, 23v, 23w. The lower arm 111 and the upper arm 123 are connected to each other at the middle side electrodes 55u, 55v, and 55w, and constitute a two-stage inverter circuit in each of the U, V, and W phases.

  FIG. 15 is a diagram illustrating a configuration of an inverter circuit mounted on the second motor drive circuit 160 according to the fifth embodiment. FIG. 15A is a diagram illustrating a cross-sectional configuration of an inverter circuit mounted on the second motor drive circuit 160 of the fifth embodiment. In FIG. 15A, the lower arm 111 and the upper arm 123 are pressed against each other, but the lower arm 111 includes semiconductor elements 12u, 12v, 12w, a spacer electrode 31 and a first electrode corresponding to the U phase, V phase, and W phase, respectively. One middle-side electrode 56u, 56v, 56w and a three-phase common low-side electrode 41 are provided. Similarly, the upper arm 123 includes the semiconductor elements 13u, 13v, 13w, the spacer electrode 31, the second middle side electrodes 57u, 57v, 57w, and the high side common to the three phases corresponding to the U phase, the V phase, and the W phase, respectively. An electrode 61 is provided. The first middle side electrodes 56u, 56v, 56w and the second middle side electrodes 57u, 57v, 57w are in pressure contact. The second motor drive circuit 160 can be cooled by cooling with cooling tubes 180 from both outer sides of the low side electrode 41 and the high side electrode 61.

  FIG. 15B is a perspective view of an inverter circuit mounted on the second motor drive circuit 160 of the fifth embodiment. As shown in FIG. 15B, the low-side electrode 41 of the lower arm 111 and the first middle-side electrodes 56u, 56v, 56w have lead electrode portions. On the other hand, the upper arm 123 shows the high side electrode 61, but the second middle side electrodes 57u, 57v, 57w are formed on the back side of the upper arm 123 and are not shown. . The high side electrode 61 has a lead electrode portion, but the second middle side electrodes 57u, 57v, and 57w do not have a lead electrode portion. The extraction electrode portions of the electrodes 56u, 56v, 56w are configured to be extraction electrodes common to the first middle side electrodes 56u, 56v, 56w and the second middle side electrodes 57u, 57v, 57w.

  FIG. 16 is an exploded perspective view of the semiconductor device according to the fifth embodiment. As shown in FIG. 16, the first-stage power module 156 is configured to be sandwiched between insulating plates 190 and sandwiched from both surfaces with a cooling tube 180 to be cooled with high efficiency. On the other hand, the second motor driving circuit 160 configured as a two-stage power module is cooled from both sides in a two-stage stacked state. The second motor drive circuit 160 is pressed by a cooler pressurizing spring 175 and functions as a power module.

  In the fifth embodiment, the example of fixing by press contact has been described. However, the semiconductor device according to the first to third embodiments can also be applied to the second motor drive circuit 160.

  FIG. 17 is a cross-sectional view showing an example of a semiconductor device according to a sixth embodiment of the present invention before bonding. In FIG. 17, the lower arm 110 and the upper arm 124 are shown. Since the configuration of the lower arm 110 is the same as that of the semiconductor device according to the first embodiment, the same reference numerals are given to the respective components. The description is omitted.

  On the other hand, the upper arm 124 includes the high-side electrode 60, the second semiconductor element 11, the second rectifying element 21, the control terminal 71, the bonding wire 80, the solder 90, and the sealing resin 100. This is the same as the upper arm 120 of the semiconductor device according to the first embodiment, but the plate-like middle side electrode 51 is eliminated and the columnar middle side electrode 58 is used. Different from semiconductor devices. The middle side electrode 58 is the electrode used as the spacer electrode 30 in the first embodiment, but in the sixth embodiment, the columnar spacer electrode 30 is exposed and used as the middle side electrode 58. The middle side electrode 58 may have any shape as long as it has an intermediate potential that is the same as that of the middle side electrode 50 of the lower arm 110. Therefore, in the sixth embodiment, the columnar spacer electrode 30 is exposed and used as the middle side electrode 58 of the upper arm 124. With such a configuration, the flat middle-side electrodes 51, 52, and 53 can be removed to make the semiconductor device more compact, and the demand for small size and high output can be met. Moreover, it can be comprised with the middle side electrode 58 whose area is smaller than the flat 1st middle side electrode 50, and can comprise a semiconductor device at low cost.

  In this case, the height of the sealing resin 100 is configured to be lower than the height of the middle side electrode 58 so that the middle side electrode 58 can be reliably joined to or pressed against the middle side electrode 50. That is, the middle side electrode 58 is provided so as to be exposed from the surface from the sealing resin 100 and has a protruding shape. Therefore, the middle side electrode 58 may be called a protruding electrode.

  In addition, since the upper arm 124 and the lower arm 110 are both resin-sealed before bonding, the degree of adhesion with the sealing resin 100 at the interface between the middle side electrodes 50 and 58 can be accurately inspected. To 5.

  FIG. 18 is a diagram illustrating an example of the semiconductor device according to the sixth embodiment after bonding. In FIG. 18, in the semiconductor device according to Example 6, the middle side electrode 50 of the lower arm 110 and the middle side electrode 58 of the upper arm 124 are joined and integrated. As described above, a two-stage stacked power module can be configured without providing a flat middle-side electrode on the upper arm 124 side.

  In FIG. 18, a seal 105 material is provided so as to fill a gap between the lower arm 110 and the upper arm 124 of the sealing resin 100. For the middle side electrode 58 of the upper arm 124 of the semiconductor device according to the sixth embodiment, it is necessary to inspect the adhesion with the sealing resin 100 at the interface of the side surface. The side surface cannot be inspected. Therefore, in the semiconductor device according to the sixth embodiment, it is necessary to prepare a configuration that prevents intrusion of water or the like on the outer surface of the sealing resin 100. From this point of view, in FIG. 18, the gap at the boundary between the upper arm 124 and the lower arm 110 is covered with the sealing material 105 to prevent moisture from entering. As shown in FIG. 18, the sealing material 105 is formed by applying the sealing material 105 to the outer peripheral surface of the power module. As the sealing material 105, various materials can be used as long as they have low water permeability. For example, FIPG, silicone resin, urethane resin, epoxy resin, polyimide resin, polyamide resin, or the like can be used. Further, even if there is no adhesion, the rubber-based packing, gasket, O-ring, CIPG and the like function. Unlike the mounting surface of the semiconductor elements 10 and 11, peeling of the side surface of the middle side electrode 58 does not lead to the generation of stress around the semiconductor elements 10 and 11 and dielectric breakdown. Can be secured.

  FIG. 19 is a cross-sectional view showing an example of a semiconductor device according to Example 7 of the present invention. Since the semiconductor device according to the seventh embodiment has the same configuration as that of the semiconductor device according to the sixth embodiment except that the position of the sealing material 106 of the upper arm 125 is different, the same components are denoted by the same reference numerals. The description is omitted.

  In FIG. 19, in the semiconductor device according to the seventh embodiment, a sealing material 106 is applied around the side surface of the middle side electrode 58. Also in this case, substantially the same effect as the sealing material 105 of Example 6 is obtained. Further, as the material of the sealing material 106, the same material as that of the sealing material 105 can be used.

  According to the semiconductor devices according to the sixth and seventh embodiments, the flat middle side electrodes of the upper arms 124 and 125 can be eliminated, so that the size and cost can be reduced.

  FIG. 20 is a sectional view showing an example of a semiconductor device according to Example 8 of the present invention. The semiconductor device according to the eighth embodiment includes a lower arm 110 and an upper arm 126. Since the configuration of the lower arm 110 is the same as that of the semiconductor device according to the first embodiment, the same reference numerals are given to the respective components and the description thereof is omitted.

  On the other hand, the upper arm 126 is common to the middle side electrode 58 of the semiconductor device according to the sixth embodiment in that the electrode immediately above the second semiconductor element 11 and the second rectifying element 21 is the middle side electrode 59. However, the shape is different from the middle side electrode 58 of the sixth embodiment. The middle side electrode 59 has a U-shaped cross-sectional shape so as to be connected across the second semiconductor element 11 and the second rectifying element 21. Thus, a spacer electrode that integrates the second semiconductor element 11 and the second rectifying element 21 may be provided, and this may be used as the middle side electrode 59. Since the other components of the upper arm 126 are the same as those of the lower arm 124 of the semiconductor device according to the sixth embodiment, the same reference numerals are used and description thereof is omitted.

  The middle electrode 59 does not use the spacer electrode 30 as in the sixth embodiment, but the area is significantly smaller than the flat second middle side electrode 51 of the semiconductor device according to the first embodiment. ing. In addition, the middle side electrode 59 is joined to the second semiconductor element 11 and the second rectifying element 21 at a portion where the middle side electrode 59 is larger than the second semiconductor element 11 and the second rectifying element 21 in the same manner as the spacer electrode 30. Therefore, it functions as a kind of spacer electrode. As described above, the spacer electrode provided immediately above the second semiconductor element 11 and the second rectifying element 21 is used as the bonding middle side electrode 59 whose surface is exposed, thereby reducing the number of middle side electrodes by one. Therefore, it can be configured in a small size and the manufacturing cost can be reduced. The middle side electrode 59 has a larger area than the flat second middle side electrodes 51, 52, and 53 that cover the entire second semiconductor element 11 and the second rectifying element 21 shown in the first to third embodiments. Since it is much smaller, the cost can be further reduced from this point.

  Similarly to the sixth embodiment, the middle side electrode 59 is provided so that the surface thereof is exposed from the sealing resin 100 and protrudes from the surface of the sealing resin 100. That is, the sealing resin 100 is configured to be lower in height than the surface of the middle side electrode 59. In this way, by configuring the middle side electrode 59 as a protruding electrode whose surface protrudes from the surface of the sealing resin 100, the bonding with the first middle side electrode 50 on the lower arm 100 side is ensured even in a small area. Can be done.

  In the semiconductor device according to the eighth embodiment, it is preferable to provide the sealing materials 105 and 106 on the outer side of the sealing resin 100 or the side surface of the middle side electrode 59 as in the sixth and seventh embodiments. Thereby, infiltration of water can be prevented reliably.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  In particular, in the first to eighth embodiments, the example in which the upper arm is joined to the lower arm has been described. However, as long as the middle side electrodes are joined, the upper arm and the lower arm may be configured to be reversed. Even in this case, the present embodiment can be preferably applied.

  The present invention can be used for a power module such as an inverter using a semiconductor element.

10, 11 Semiconductor element 20, 21 Rectifier 30 Spacer electrode 40, 41 Low side electrode 50-53, 55u-w, 56u-w, 57u-w, 58, 59 Middle side electrode 54, 101 Fitting structure 54a, 101a Convex Portion 54b, 101b Recess 60, 61 High side electrode 70, 71, 79 Control terminal 80, 89 Bonding wire 90 Solder 100 Sealing resin 105, 106 Sealing material 110, 111 Lower arm 120-125 Upper arm 130, 131 Bonding layer 132 pressure contact interface 135 joint 140 power supply 150 first motor drive circuit 160 second motor drive circuit 170 cooler fixing housing 171 holding spring holding boss 175 holding spring 180 cooling tube 181 fin 190 insulating plate

Claims (10)

A low-side electrode and a first middle-side electrode that are electrically connected to each surface of the first semiconductor element so as to sandwich the first semiconductor element from both sides, A first resin mold molded with a sealing resin so that the outer surfaces of the electrode and the first middle side electrode are exposed;
A second semiconductor element, and a high-side electrode and a second middle-side electrode are provided in conduction with each surface of the second semiconductor element so as to sandwich the second semiconductor element from both sides, A second resin mold molded with a sealing resin so that the outer surfaces of the high side electrode and the second middle side electrode are exposed;
The outer surfaces of the first middle side electrode and the second middle side electrode are bonded together by a bonding material having no conductivity,
The first middle side electrode and the second middle side electrode each have a first extraction electrode portion and a second extraction electrode portion that protrude outward from the side surface of the sealing resin,
A semiconductor device characterized in that the first lead electrode portion and the second lead electrode portion are electrically connected by bonding.   The bonding with the non-conductive bonding material is determined by a concave / convex fitting structure formed on the facing surface of the sealing resin of the first resin mold and the sealing resin of the second resin mold. The semiconductor device according to claim 1, wherein the semiconductor device is performed.   The bonding with the non-conductive bonding material is performed by being positioned by a concave / convex fitting structure formed on an opposing surface of the first middle side electrode and the second middle side electrode. The semiconductor device according to claim 1 or 2. The area between the low side electrode and the first middle side electrode and between the high side electrode and the second middle side electrode is larger than that of the first semiconductor element and the second semiconductor element. Each is provided with a small columnar spacer electrode,
At least one of the low side electrode and the first middle side electrode is electrically connected to the first semiconductor element through the spacer electrode, and at least one of the high side electrode and the second middle side electrode is 4. The semiconductor device according to claim 1, wherein the semiconductor device is electrically connected to the second semiconductor element through a spacer electrode. 5. The first resin mold includes a third and a fourth semiconductor element connected in parallel to the first semiconductor element on the low-side electrode side to form a three-phase low-side circuit,
The second resin mold includes a fifth and a sixth semiconductor element connected in parallel on the high side electrode side to the second semiconductor element to form a three-phase high side circuit,
The third middle side electrode of the third semiconductor element and the fifth middle side electrode of the fifth semiconductor element, the fourth middle side electrode of the fourth semiconductor element, and the sixth semiconductor element The sixth middle side electrodes are bonded together by a bonding material having no conductivity,
The third middle side electrode and the fifth middle side electrode each have a third extraction electrode portion and a fifth extraction electrode portion that protrude outward from the side surface of the sealing resin. Are electrically connected by joining the lead electrode portion and the fifth lead electrode portion,
The fourth middle side electrode and the sixth middle side electrode each have a fourth extraction electrode portion and a sixth extraction electrode portion that protrude outward from the side surface of the sealing resin, and the fourth 5. The inverter circuit that is electrically connected by joining the lead electrode portion and the sixth lead electrode portion to drive a three-phase AC motor is formed according to claim 1. The semiconductor device described. A low-side electrode and a first middle-side electrode that are electrically connected to each surface of the first semiconductor element so as to sandwich the first semiconductor element from both sides, A first resin mold molded with a sealing resin so that the outer surfaces of the electrode and the first middle side electrode are exposed;
A second semiconductor element, and a high-side electrode and a second middle-side electrode are provided in conduction with each surface of the second semiconductor element so as to sandwich the second semiconductor element from both sides, A second resin mold molded with a sealing resin so that the outer surfaces of the high side electrode and the second middle side electrode are exposed;
The outer surfaces of the first middle side electrode and the second middle side electrode are integrally fixed by bonding or pressure welding and electrically connected,
Either one of the first middle side electrode and the second middle side electrode is a spacer electrode provided such that the surface is exposed from the first resin mold or the second resin mold,
The other of the first middle side electrode and the second middle side electrode is a plate-like electrode having a larger area than the spacer electrode.   The spacer electrode includes a columnar shape having a smaller area than the first semiconductor element and the second semiconductor element, and the surface protrudes from the first resin mold or the second resin mold. The semiconductor device according to claim 6.   The semiconductor device according to claim 6, wherein a side surface between the first resin mold and the second resin mold is sealed with a sealing material.   The semiconductor device according to claim 6, wherein a space between a side surface of the spacer electrode and the sealing resin is sealed with a sealing material. A first semiconductor element is disposed between the low side electrode and the first middle side electrode, and two surfaces of the first semiconductor element, the low side electrode, and the first middle side electrode are conductively fixed by soldering. A first resin mold forming step of forming a first resin mold by molding with a sealing resin so that the outer surfaces of the low side electrode and the first middle side electrode are exposed in a state where
A second semiconductor element is disposed between the high side electrode and the second middle side electrode, and two surfaces of the second semiconductor element are electrically connected to the high side electrode and the second middle side electrode by solder bonding. A second resin mold forming step of forming a second resin mold by molding with a sealing resin so that the outer surfaces of the high side electrode and the second middle side electrode are exposed in a fixed state When,
A first resin mold inspection step of inspecting an interface between the low side electrode and the sealing resin of the first resin mold and an interface between the first middle side electrode and the sealing resin by ultrasonic flaw detection;
A second resin mold inspection step of inspecting an interface between the high side electrode and the sealing resin of the second resin mold and an interface between the second middle side electrode and the sealing resin by ultrasonic flaw detection;
In the first resin mold inspection step and the second resin mold inspection step, the first middle side electrode of the first resin mold and the second resin mold that are determined as non-defective products, and the second resin mold And integrating the outer surfaces of the middle side electrodes with a non-conductive bonding material and conducting the first middle side electrode and the second middle side electrode,
The first middle side electrode and the second middle side electrode each have a first extraction electrode portion and a second extraction electrode portion that protrude outward from the side surface of the sealing resin,
Conductivity between the first middle side electrode and the second middle side electrode in the integration step is performed by joining the first lead electrode portion and the second lead electrode portion. A method for manufacturing a semiconductor device.

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